In his physics class, Kevin took 4 exams. His scores were 83, 88, 89, and 80. What was his average score on the exams?
Explanation: The average is the sum of his scores divided by the number of scores. There are 4 scores and their sum is $83 + 88 + 89 + 80 = 340$ His average score is $340 \div 4 = 85$.